Organic light-emitting diode (OLED) display panels are considered to have the most potential to be the next generation of new flat panel display technology thanks to their wide variety of outstanding advantages including active illumination, thinness, a large viewing angle, fast response, good energy-saving performance, a wide temperature tolerance range and capabilities of flexible and transparent display.
Currently, there are two well developed full-color techniques for OLED display panels: color filters (CF) and RGB (the three primary colors: red, green and blue) pixels.
Like those used in liquid crystal display (LCD) panels, color filters can also be used in OLED display panels for the full-color effect. In these cases, white-light OLEDs serve as backlight playing the same role as both backlight and liquid crystal molecules in LCD panels, and color filters are placed thereon to form red, green and blue sub-pixels. In this way, the resolution and large panel requirements can be satisfied. However, as light loses significant energy when passing through the color filters, such display panels suffer from significant power consumption.
In order to address the high power consumption issue, full-color OLED display panels using RGB pixels have been utilized.
FIG. 1 schematically illustrates an existing OLED display panel utilizing RGB pixels. As shown in FIG. 1, the OLED display panel is formed in a paralleled RGB manner and has multiple pixel units Pixel each including, horizontally aligned, one red sub-pixel unit R, one green sub-pixel unit G and one blue sub-pixel unit B. The sub-pixel units in the OLED display panel are arranged in a matrix and each of them has a display section 1 and a non-display section 2. Specifically, the display section 1 of each sub-pixel unit is provided with a cathode, an anode and an electroluminescent layer (organic emission layers) disposed between the cathode and the anode to generate light of the prescribed color so as to enable the display of an image. The electroluminescent layer is usually fabricated by vapor deposition. During the fabrication of the conventional display panel, three vapor deposition processes are carried out to form electroluminescent layers for the corresponding colors (red, green and blue) in the display sections 1 of the pixel units.
FIG. 2 schematically illustrates another existing OLED display panel utilizing RGB pixels. As shown in FIG. 2, the OLED display panel formed in an RGB matrix manner has multiple pixel units Pixel each including one red sub-pixel unit R, one green sub-pixel unit G and one blue sub-pixel unit B. Two out of these three sub-pixel units, for example, the red sub-pixel unit R and the green sub-pixel unit G, are arranged in a column, and the third sub-pixel unit, for example, the blue sub-pixel unit B, is disposed in another column. As such, the sub-pixel units in the OLED display panel are arranged in a matrix.
As technology evolves, users are increasingly demanding for OLED display panels with higher resolution, and the conventional RGB pixel arrangements have fallen short in meeting the increasingly higher PPI (pixels per inch) requirements.